Lubricating oil or fuel containing sludge-dispersing additive

ABSTRACT

High molecular weight, oil-soluble, mono- and polycarboxylic acid esters are posttreated with mono- or polycarboxylic acid acylating reagents to provide compositions useful as dispersants in lubricants and fuels. Esters of polyisobutenyl-substituted succinic anhydride and pentaerythritol posttreated with maleic anhydride exemplify the process and compositions of this invention.

United States Patent Le Suer [54] LUBRICATING OIL OR FUEL CONTAININGSLUDGE-DISPERSING ADDITIVE [52] US. Cl ..252/56 R, 252/56 D, 252/57,44/70 [51] Int. Cl. ..Cl0m 1/26 [58] FieldoiSearch ..252/56,56 D,57;44/70; 260/485 G [56] References Cited UN lTED STATES PATENTS2,800,500 7/1957 Matuszak et al ..260/485 Feb, 1, i972 3,000,917 9/1961Babayan ..260/485 X 3,170,898 2/1965 Verdol ..260/485 X 3,194,791 7/1965Wilson et a1. .....260/485 X 3,197,409 7/1965 de Vrics ..252/563,255,108 6/1966 Wiese ..252l56 X 3,331,776 7/1967 Krukziener ..252/562,976,245 3/1961 Copes ..Z52/57 3,522,179 7/1970 Le Suer ..252/56 DPrimary Examiner-Daniel E. Wyman Assistant Examiner-W. CannonAttorney-Roger Y. K. Hsu, William H. Pittman and James W. Adams, Jr.

[5 7] ABSTRACT High molecular weight, oil-soluble, mono-andpolycarboxylic acid esters are posttreated with monoor polycarboxylicacid acylating reagents to provide compositions useful as dispersants inlubricants and fuels. Esters of polyisobutenyl-substituted succinicanhydride and pentaerythritol posttreated with maleic anhydrideexemplify the process and compositions of this invention.

13 Claims, No Drawings LUBRICATING 01L R FUEL CONTAINING SLUDGE-lDlSPERSlNG ADDlTlVE This is a continuation-in-part of copendingapplication of Ser. No. 717,429 tiled Mar. 29, 1968, now abandoned.

This invention relates to a process for treating oil-soluble carboxylicacid esters, to the compositions of matter resulting from this process,and to lubricants and fuels containing these compositions of matter. inparticular, the invention is concerned with the posttreatment of estersof high molecular weight carboxylic acids with monoor polycarboxylicacid acylating reactants, the compositions of matter produced bytreating the esters with these acylating reactants and to lubricants andfuels containing these compositions.

The prior art discloses many esters of high molecular weight carboxylicacids as useful additives in fuel and lubricant compositions, forexample, French Pat. No. 1,396,645; British Pat.' Nos. 981,850 and1,055,337; and US. Pat. Nos. 3,255,108; 3,3 1 1,558; 3,331,776; and3,346,354; and commonly assigned copending applications Ser. No.567,320, filed July 22, 1966, now U.S. Pat. No. 3,381,022, and Ser. No.712,627 filed Mar. 13, 1968 now U.S. Pat. No. 3,542,678. The presentinvention is directed to a process for posttreatirig esters of thisgeneral type with at least one carboxylic acid acylating reactant toprovide novel compositions of matter also useful as additives inlubricants and fuels.

In accordance with the foregoing, it is a principal object of thisinvention to provide a novel chemical process.

A further object of the invention is to provide a process forposttreating certain esters with carboxylic acid acylating reactants.

An additional object is to provide novel compositions of matter producedby posttreating of certain carboxylic acid esters with carboxylic acidacylating reactants.

A still further object is to provide novel lubricants and fuelscontaining compositions produced by posttreating certain esters withcarboxylic acid acylating reactants.

These and other objects of this invention are accomplished by providinga process comprising contacting (A) at least one oil-soluble ester of amonoor polycarboxylic acid and a polyhydric alcohol where the-carboxylicacid moiety of the ester is characterized by at least about 50 aliphaticcarbon atoms exclusive of the carboxyl carbon atoms and the alcoholmoiety contains up to about 45 aliphatic carbon atoms with (B) at leastone acylating reactant selected from monoor polycarboxylic acids havingone to about 30 carbon atoms, anhydrides thereof, acyl halides thereof,or mixtures of two or more such acylating agents. The compositionsproduced by this process, the process, and lubricants and fuelscontaining the compositions are described in more detail hereinafter.

The esters to be posttreated with the C,-C carboxylic acid acylatingreactants according to the present invention are esters of monoandpolycarboxylic acids containing at least about 50 aliphatic carbon atomsexclusive of the carboxyl carbon atoms. The alcohol moiety of the esterscontemplated is derived from a polyhydric alcohol containing up to about40 aliphatic carbon atoms. These esters are known in the prior art orcan be readily prepared from available intermediates according toconventional procedures. Since the foregoing enumerated patents disclosemany esters of this type and various processes for their preparation,these patents are incorporated herein for the sake of brevity.

For the most part, these patents are directed to esters of substitutedsuccinic acids and aliphatic polyhydric alcohols. However, the presentinvention contemplates the posttreatment of similar esters prepared frommonocarboxylic acids as well as polycarboxylic acids other than succinicacids. Such esters can be prepared from these mono and polycarboxylicacid acylating agents and the appropriate aliphatic alcohols byfollowing the same general procedure as used in the preparation of thesuccinic acid esters in the above patents.

The acyl radical of he esters to be posttreated is derived from a monoorpolycarboxylic acid. One particularly important characteristic of theacyl radical is its size. Thus, the radical should contain at leastabout 50 aliphatic carbon atoms exclusive of the carboxyl carbon atoms.This limitation is based upon both oil-solubility considerations and theeffectiveness of the compositions as additives in lubricants and fuels.Another important aspect of the acyl radical is that it preferablyshould be substantially saturated, i.e., at least about 95 percent ofthe total number of the carbon-to-carbor| covalent linkages thereinpreferably should be saturated linkages. In an especially preferredaspect of the invention, at least about 98 percent of these covalentlinkages are saturated. Obviously, all of the covalent linkages may besaturated. A greater degree of unsaturation renders the esters moresusceptible to oxidation, degradation, an polymerization and thislessens the effectiveness of the final products as lubricant and fueladditives.

In addition, the acyl radical of the esters should be substantially freefrom oil-solubilizing pendant groups, that is, groups having more thanabout six aliphatic carbon atoms. Although, some such oil-solubilizingpendant groups may be present, they preferably will not exceed one suchgroup for every 25 aliphatic carbon atoms in the principal hydrocarbonchain of the acyl radical.

The acyl radical may contain polar substituents provided that the polarsubstituents are not present in proportions sufficiently large to altersignificantly the hydrocarbon character of the radical. Typical suitablepolar substituents are halo, such as chloro and bromo, oxo, oxy, formyl,sulfonyl, suliinyl, thio, nitro, etc. Such polar substituents, ifpresent, preferably will not exceed 10 percent by weight of the totalweight of the hydrocarbon portion of the carboxylic acid radicalexclusive of the carboxyl group.

Carboxylic acid acylating agents suitable for preparing the esters arewell known in the art and have been described in detail, for example, inUS. Pat. Nos. 3,087,936; 3,163,603; 3,172,892; 3,189,544; 3,219,666;3,272,746; 3,288,714; 3,306,907; 3,331,776; 3,340,281; 3,341,542; and3,346,354. In the interest of brevity, these patents are incorporatedherein for their disclosure of suitable monoand polycarboxylic acidacylating agents which can be used for the preparation of the estersused as starting materials in the present invention.

As disclosed in the foregoing patents, there are several processes forpreparing the acids. Generally, the process involves the reaction of 1)an ethylenically unsaturated carboxylic acid, acid halide, or anhydridewith (2) an ethylenically unsaturated hydrocarbon containing at leastabout aliphatic carbon atoms or a chlorinated hydrocarbon containing atleast about 50 aliphatic carbon atoms at a temperature within the rangeof about -300 C. The chlorinated hydrocarbon or ethylenicallyunsaturated hydrocarbon reactant can, of course, contain polarsubstituents, oil-solubilizing pendant groups, and be unsaturated withinthe general limitations explained hereinabove. It is these hydrocarbonreactants which provides most of the aliphatic carbon atoms present inthe acyl moiety of the final products.

When preparing the carboxylic acid acylating agent according to one ofthese two processes, the carboxylic acid reactant usually corresponds tothe formula R,,-(ICOOl-l),,, where R,, is characterized by the presenceof at least one ethylenically unsaturated carbon-to-carbon covalent bondand n is an integer from 1 to 6 and preferably 1 or 2. The acidicreactant can also be the corresponding carboxylic acid halide,anhydride, ester, or other equivalent acylating agent and mixtures ofone or more of these. Ordinarily, the total number of carbon atoms inthe acidic reactant will not exceed 10 and generally will not exceedsix. Preferably the acidic reactant will have at least one ethyleniclinkage in an a,B-position with respect to at least one carboxylfunction. Exemplary acidic reactants are acrylic acid, methacrylic acid,maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconicanhydride, citraconic acid, citraconic anhydride, niesaconic acid,glutaconic acid, chloromaleic acid, aconitic acid, crotonic acid,methylcrotonic acid, sorbic acid, 3-hexenoic acid, IO-decenoic acid, andthe like. Due to considerations of economy and availability, these acidreactants usually employed are acrylic acid, methacrylic acid, maleicacid, and maleic anhydride.

As is apparent from the foregoing discussion, the carboxylic acidacylating agents may contain cyclic and/or aromatic groups. However, theacids are essentially aliphatic in nature and in most instances, thepreferred acid acylating agents are aliphatic monoand polycarboxylicacids, anhydrides, and halides. Y

The substantially saturated aliphatic hydrocarbon-substituted succinicacid and anhydrides are especially preferred as acylating agents in thepreparation of the esters used as starting materials in the presentinvention. These succinic acid acylating agents are readily prepared byreacting maleic anhydride with a high molecular weight olefin or achlorinated hydrocarbon such as a chlorinated polyolefin. The reactioninvolves merely heating the two reactants at a temperature of aboutl-300 C., preferably, l00200 C. The product from such a reaction is asubstituted succinic anhydride where the substituent is derived from theolefin or chlorinatedhydrocarbon as described in the above-citedpatents. The product may be hydrogenated to remove all or a portion ofany ethylenically unsaturated covalent linkages by standardhydrogenation procedures, if desired. The substituted succinicanhydrides may be hydrolyzed by treatment with water or steam to thecorresponding acid and either the anhydride or the acid may be convertedto the corresponding acid halide or ester by reacting with phosphorushalide, phenols, or alcohols.

The ethylenically unsaturated hydrocarbon reactant and the chlorinatedhydrocarbon reactant used in the preparation of the acylating agents areprincipally the high molecular weight, substantially saturated petroleumfractions and substantially saturated olefin polymers and thecorresponding chlorinated products. The polymers and chlorinatedpolymers derived from mono-olefins having from two to about 30 carbonatoms are preferred. The especially useful polymers are the polymers ofl-mono-olefins such as ethylene, propene, l-butene, isobutene, l-hexene,l-octene, Z-methyl-l-heptene, 3-cyclohexyll-butene, and2-methyl-5-propyl-l-hexene. Polymers of medial olefins, i.e., olefins inwhich the olefinic linkage is not at the terminal position, likewise areuseful. These are exemplified by Z-butene, 3-pentene, and 4-octene.

The interpolymers of l-mono-olefins such as illustrated above with eachother and with other interpolymerizable olefinic substances such asaromatic olefins, cyclic olefins, and polyolefins, are also usefulsources of the ethylenically unsaturated reactant. Such interpolymersinclude for example, those prepared by polymerizing isobutene withstyrene, isobutene with butadiene, propene with isoprene, propene withisobutene, ethylene with piperylene, isobutene with chloroprene,isobutene with p-methyl-styrene, l-hexene with l,3-hexadiene, l-octenewith l-hexene, l-heptene with l-pentene, 3- methyll-butene withl-octene, 3,3-dimethyl-l-pentene with l-hexene, isobutene with styreneand piperylene, etc.

For reasons of oil solubility and stability, the interpolymerscontemplated for use in preparing the acylating agents of this inventionshould be substantially aliphatic and substantially saturated, that is,they should contain at least about 80 percent and preferably about 95percent, on a weight basis, of units derived from aliphaticmono-olefins. Preferably, they will contain no more than about 5 percentolefinic linkages based on the total number of the carbon-to-carboncovalent linkages present.

The chlorinated hydrocarbons and ethylenically unsaturated hydrocarbonsused in the preparation of the acylating agents can have molecularweights of from about 700 up to about 100,000 or even higher. Thepreferred reactants are the above-described polyolefins and chlorinatedpolyolefins having an average molecular weight of about 700 to about5,000. When the acylating agent has a molecular weight in excess ofabout 10,000, the acylated nitrogen composition also possess viscosityindex improving qualities.

In lieu of the high molecular weight hydrocarbons and chlorinatedhydrocarbons discussed above, hydrocarbons containing activating polarsubstituents which are capable of activating the hydrocarbon molecule inrespect to reaction with an ethylenically unsaturated acid reactant maybe used in the above-illustrated reactions for preparing the acylatingagents. Such polar substituents include sulfide and disulfide linkages,and nitro, mercapto, carbonyl and formyl radicals. Examples of thesepolar-substituted hydrocarbons include polypropene sulfidedi-polyisobutene disulfide, nitrated mineral oil, di-polyethylenesulfide, brominated polyethylene,

etc.

The acylating agents may also be prepared by halogenating a highmolecular weight hydrocarbon such s the abovedescribed olefin polymersto produce a polyhalogenated product, converting the polyhalogenatedproduct to a polynitrile, and then hydrolyzing the polynitrile. They maybe prepared by oxidation of a high molecular weight polyhydric alcoholwith potassium permanganate, nitric acid, or asimilar oxidizing agent.Another method for preparing such polycarboxylic acids involves thereaction of an olefin or a polar-substituted hydrocarbon such as achloropolyisobutene with an unsaturated polycarboxylic acid 7 such as2-pentent-l,3',5- tricarboxylic acid prepared by dehydration of citricacid. Monocarboxylic acid acylating agents may be obtained by oxidizinga monoalcohol withv potassium permanganate or by reacting a halogenatedhigh molecular weight olefin polymer with a ketene. Another convenientmethod for preparing monocarboxylic acid involves the reaction ofmetallic sodium with an acetoacetic ester or a malonic ester of analkanol to form a sodium derivative of the ester and the subsequentreaction of the sodium derivative with a halogenated high molecularweight hydrocarbon such as brominated wax or brominated polyisobutene.

Monocarboxylic and polycarboxylic acid acylating agents can also beobtained by reacting chlorinated monoand polycarboxylic acids,anhydrides, acyl halides, and the like with ethylenically unsaturatedhydrocarbons or ethylenically unsaturated substituted hydrocarbons suchas the polyolefins and substituted polyolefins described hereinbefore inthe manner described in U.S. Pat. No. 3,340,281.

The monocarboxylic and polycarboxylic acid anhydrides are obtained bydehydrating the corresponding acids. Dehydration is readily accomplishedby heating the acid to a temperature above about 70 C., preferably inthe presence of a dehydration agent, e.g., acetic anhydridc. Cyclicanhydrides are usually obtained from polycarboxylic acids having acidradicals separated by no more than three carbon atoms such assubstituted succinic or glutaric acid, whereas linear anhydrides areobtained from polycarboxylic acids having the acid radicals separated byfour or more carbon atoms. A

The'acid halides of the monocarboxylic and polycarboxylic acids can beprepared by the reaction of the acids or their anhydrides with ahalogenating agent such as phosphorus tribromide, phosphoruspentachloride, or thionyl chloride.

The esters which are to be posttreated are generally prepared byreacting he carboxylic acid acylating agent, preferably the acid per so,its acyl chloride, or an anhydride thereof, with an aliphatic polyhydricalcohol containing up to about '40 aliphatic carbon atoms according toconventional processes for preparing carboxylic acid esters. Thesealcohols are characterized by two to [0 hydroxyl groups and can be quitediverse in structure and chemical composition. Typical alcohols arealkylene glycols such as ethylene glycol, propylene glycol, trimethyleneglycol, butylene glycol, and polyglycols such as diethylene glycol,triethylene glycol, tetraethylene glycol, dipropylene glycol,tripropylene glycol, dibutylene glycol, tributylene glycol, and otheralkylene glycols and polyalkylene glycols in which the alkylene radicalcontains from two to about eight carbon atoms. Other useful polyhydricalcohols include glycerol, monomethyl ether of glycerol,penthaerythritol, 9,l0dihydroxystearic acid, the ethyl ester of9,l0-dihydroxystearic acid, 3-chloro-l,2- propanediol l,2-butanediol,1,4-butanediol, 2,3-hexanediol, pinacol, erythritol, arabitol, sorbitol,mannitol, l,2-cylcohexanediol, l,4-cyclohexanediol, l,4-(2-hydroxyethyl)-cyclohex' ane, l,4-dihydroxy-2-nitro-butane, il,4-di(2-hydroxyethyl)- benzene, the carbohydrates such as glucose,ramnesc, mare nose, glyceraldehyde, and galactose, and the like, aminoalcohols such as di(Z-hydroxyethyl)amine, tri-(3-hydroxypropyl)amine,N,N-di(hydroxyethyl)ethylenediamine, copolymer of allyl alcohol andstyrene, N,N-di-(2-hydroxylethyl) glycine and esters thereof with lowermonoand polyhydric aliphatic alcohols etc.

lncluded within this group of aliphatic alcohols are those polyhydricalcohols containing at least three hydroxyl groups, at least one ofwhich has been esterified with a monocarboxylic acid having from eightto about 30 carbon atoms such as octanoic acid, oleic acid, stearicacid, linoleic acid, dodecanoic acid, or tall oil acid Examples of suchpartially esterified polyhydric alcohols are the mono-oleate ofsorbitol, the mono-oleate of glycerol, the mono-stearate of glycerol,the distearate of sorbitol, and the di-dodecanoate of erythritol.

A preferred class of esters are those prepared from aliphatic alcoholscontaining up to carbon atoms, and especially those containing three to10 carbon atoms. This class of alcohols includes glycerol, erythritol,pentaerythritol, gluconic acid, glyceraldehyde, glucose, arabinose,1,7-heptanediol, 2,4-heptanediol, 1,2,3-hexanetriol, l,2,4-hexanetriol,1,2,5- hexanetriol, 2,3,4-hexanetriol, 1,2,3-butanetriol,1,2,4-butanetriol, quinic acid, 2,2,6,6-tetrakis-(hydroxymethyD-cyclohexanol, 1,10-decanediol, digitalose, and the like. The estersprepared from aliphatic alcohols containing at least three hydroxylgroups and up to 10 carbon atoms are particularly preferred.

An especially preferred class of polyhydric alcohols for preparing theesters used as starting materials in the present invention are thepolyhydric alkanols containing three to 10, especially three to sixcarbon atoms and having at least three hydroxyl groups. Such alcoholsare exemplified in the above specifically identified alcohols and arerepresented by glycerol, erythritol, pentaerythritol, mannitol,sorbitol, 1,2,4- hexanetriol, and the like.

The acylating reagents used in the posttreatment process are the C -Cmonoor polycarboxylic acids, their halides, anhydrides, or mixturesthereof. The acids may be aromatic, acyclic, or alicyclic acids and theymay contain one or more substituents such as halo (e.g., Br, Cl, 1),lower alkoxy (e.g., methoxy, ethoxy, butoxy, pentoxy), lower alkyl(e.g., methyl, isopropyl, isobutyl, heptyl), lower alkylthio (e.g.,propylmercapto, hexylmercapto, ethylmercapto)nitro, amino, loweralkylamino, di(lower alkyl)amino, and the like. Illustrative acylatingreagents include formic acid, acetic acid, chloroacetic acid, aceticanhydride, butyric acid, cyclohexanoic acid, tetrapropylene-substitutedsuccinic acid, fumaric acid, benzoic acid, n-toluic acid, salicyclicacid, phthalic acids, 4-propoxy-benzoic acid, phenyl acetic acid,fl-phenyl propionic acid, and the like.

However, the C to C saturated or unsaturated aliphatic monoordicarboxylic acids, acid halides, or anhydrides constitute a preferredclass of acylating reagents. These acids are generally free fromnonhydrocarbon substituents and can be straight or branched chainaliphatic acids. Examples of this class of acylating reagents are formicacid, acetic acid, hexanoic acid, maleic anhydride,tetrapropylene-substituted succinic anhydride, oxalic acid, adipic acid,lauric acid, oleic acid, linoleic acid, stearic acid, tall oil acid,dodecanoic acid, octanoic acid, Z-ethyl-hexanoic acid, undecanoic acid,octadecanoic acid, eicosanoic acid, docosanoic acid, triacontanoic acid,acrylic acid, methacrylic acid, crotonic acid, isocrotonic acid, sorbicacid, malonic acid, succinic anhydride, glutaric acid, pimelic acid,azelaic acid, sebacic acid, glutaconic acid, citraconic acid, itaconicacid, mesaconic acid, allylsuccinic acid, cetylmalonic acid, and thelike. Such acylating reagents having up to six aliphatic carbon atoms,including the carboxyl carbon atoms, are a particularly preferred classof acylating agents. The dicarboxylic acids in this latter class ofacylating agents, particularly maleic acid, maleic anhydride, succinicanhydride, succinic acid, and fumaric acid are especially useful.

The specific nature of posttreatment process is not completelyunderstood but it is believed that the C C, acylating reagents esterifyfree-hydroxyl groups present in the alcoholic moiety of the estersand/or with unesterified polyhydric alcohol present in the ester. Suchfree-hydroxyl groups could be present as a result of using less than atleast a stoichiometrically equivalent amount of acylating agent relativeto polyhydric alcohol when preparing he ester (e.g., a ratio ofequivalents of high molecular weight acylating agent to polyhydricalcohol of about l:l.05 to about 1:6; generally about l:l.l to about1:4). Or the esterification process may have been terminated before allthe hydroxyl groups could react even assuming the presence of sufficientacylating agent to react with all the hydroxyl groups in the polyhydricalcohol. Moreover, the size of a given high molecular weight acylatingagent may hinder reaction with all of the hydroxyl groups on a givenpolyhydric alcohol due to spatial considerations, e.g., sterichindrance. In addition, the acylating reactant can react with othergroups present in the esters which are subject to acylation. Forexample, esters derived from amino-alcohols may form salts or amideswith the acylating reagents. Obviously, polycarboxylic acylatingreactants may combine with unesterified hydroxyl groups, amino groups,etc., on different ester molecules to form larger ester moleculesbridged by a polycarboxylic acid acylating reagent.

This invention includes as the subsequent posttreatment of esters whichhave been first posttreated with organic epoxides particularly alltyleneoxides such as ethylene oxide and propylene oxide. Such esters aredisclosed in detail in commonly assigned applicationSer. No. 712,606,filed Mar. .13, l968now abandoned. This application is incorporatedherein by reference for its disclosure of epoxide posttreated esters.

Since the specific nature of the posttreatment is not understood, it isnot possible to identify a specific ratio of ester and acylating reagentwhich will give the best results in all cases. However, if the ratio ofequivalents of ester to total equivalents of acylating reagent employedin the posttreatment process is maintained at about 1:0.05 to 1:5 andpreferably, about 1:0.] to 1:], the posttreating process will impartimproved properties to the ester, particularly improved dispersantproperties. Within these ratios, the optimum ratios for a given ester ormixture of esters and a given acylating reagent or mixture of acylatingreagents: can be determined by routine evaluation. It is not meant toimply that all of the acid used in the posttreatment process must.react. Excess acylating agent which is not soluble in the posttreatedester or an oil solution thereof can be removed by conventionalprocedures such as decantation or filtration as appropriate. Solubleexcess acylating reagent can remain in the product.

For purposes of further defining the invention only, the number ofequivalents in an ester corresponds to the number of alcoholic hydroxylgroups in the alcohol moiety regardless of whether or not they areesterified. Similarly, the number of equivalents in an acylating reagentcorresponds to the number of carboxylic acid, acid halide, or anhydridegroupspresent. Thus, an ester prepared from pentaerythritol has fourequivalents per mole; from mannitol, six; from tri-(2hydroxyethyl)amino,three. When, for example, the acylating reagent is acetic acid, octanoylchloride, or phenylacetic acid, it has one equivalent per mole; whenmaleic acid or maleic anhydride, two equivalents per mole; etc.

The posttreatment process involves merely contacting the ester andacylating reagent. This contacting" is preferably accomplished byforming a reaction mixture of the ester, and acylating reagent andmaintaining this reaction mixture at a temperature of about 50 C. up toa temperature just below the decomposition temperature of the reactantin the reaction mixture having the lowest decomposition temperature.Temperatures of about 100 C. to about 250 C., however, are preferredwith temperatures of about l-220 C. being particularly suitable.Agitation of the reaction mixture also facilitates the reaction.

The posttreatment process is normally conducted in the presence of asubstantially inert liquid diluent such as liquid hydrocarbons and halohydrocarbons, ethers, mixtures of these, and the like. Specific suitablediluents include mineral oil, naphthas, benzene, toluene, xylene,chlorobenzenes, cyclohexane, hexane, heptane, l-chlorohexane,l-bromooctane, n-amyl-ether, dimethylformamide, dimethylacetamide, etc.These same diluents are normally employed in the preparation of theesters. In fact, the usual procedure is to prepare the ester in adiluent comprising in part, at least, a synthetic or mineral lubricatingoil since they are soluble in such diluents and can be added to thelubricant or fuel in the form of a lubricating oil solution. Theacylating reagents can be mixed with such solutions in order to carryout the posttreating process of the invention.

As is obvious to those skilled in the art, the duration of theposttreating process can vary depending on the type and quantity ofester and acylating reagent, agitation of the reaction mixture,temperature, and the like.

It will be understood by those skilled in the art the carboxylic acidmoiety of an ester refers to the carboxylic acid acyl radical of theester while the alcoholic moiety refers to the oxy radical of thealcohol from which the ester is derived. Thus, in the illustrativefonnula where R and R are the residues of the carboxylic acid acylatingagents used to prepare the esters, the acyl moiety is The followingexamples further illustrate the present invention. Unless otherwiseindicated, parts and percentages refer to parts by weight and percent byweight in these examples and elsewhere in the specification and claims.

EXAMPLE 1 A carboxylic acid ester is prepared by slowly adding 3,240parts of a high molecular weight carboxylic acid (prepared by reactingchlorinated polyisobutylene and acrylic acid in a H equivalent ratio andhaving an average molecular weight of 982) to a mixture of 200 parts ofsorbitol and l,000 parts of diluent oil over a l.5-hour period whilemaintaining a temperature of l l"-l25 C. Then 400 parts of additionaldiluent oil are added and the mixture is maintained at about l95205 C.for 16 hours while blowing the mixture with nitrogen. An additional 755parts of oil are then added, the mixture cooled to 140 C., and filtered.The filtrate is an oil solution of the desired ester.

EXAMPLE 2 An esteris prepared by heating 658 parts of a carboxylic acidhaving an average molecular weight of 1,0l8 (prepared by reactingchlorinated polyisobutene with acrylic acid) with 22 parts ofpentaerythritol while maintaining a temperature of about l80-205 C. forabout l8 hours during which time nitrogen is blown through the mixture.The mixture is then filtered and the filtrate is the desired ester.

EXAMPLE 3 To a mixture comprising 408 parts of pentaerythritol and l,l00parts oil heated to l20 C. there is slowly added 2,946 parts of the acidof example l which has been preheated to C., 225 parts of xylene, and 95parts of diethylene glycol dimethylether. The resulting mixture isheated at l95-205 C., under a nitrogen atmosphere and reflux conditionsfor eleven hours, stripped to C. at 22 mm. (Hg) pressure,

and filtered. The filtrate comprises the desired ester. It is diluted toa total oil content of 40 percent.

EXAMPLE 4 A. An ester is prepared following the general procedure ofExample 1 by reacting one equivalent of a carboxylic acid chloride(prepared by reacting l mole of polyisobutene (average molecularweight-1,500) with 2.5 moles of chloroacetyl chloride according to U.S.Pat. No. 3,340,28l and thereafter removing excess chloroacetyl chloride)with three equivalents of mannitol. After filtration, the'filtrate isdiluted to a mineral oil content of 40 percent.

B. The procedure of Example 4(A) is repeated but the acid chloride isreplaced with one equivalent of an acid chloride prepared by reacting anisobutylene: propylene copolymer (average molecular weight-2,200)containing about 20 percent propylene units and chloroacetylchloride ina molar ratio of copolymer to chloroacetylchloride of l:2.5 followingthe procedure of US. Pat. No. 3,340,28 l.

Following the general procedure of Example 1, esters are prepared fromthe acylating agents and alcohols indicated in the following table inthe equivalent ratio shown. Obviously, more or less diluent can be usedas desired to facilitate handling, etc.

TABLE Acylatlng Equivalent agent ratio of Example (X) Alcohol (Y)(X):(Y)

5 A Polytiyethylene glycol (average M.W. 1:1

4 6 A Polyrggpropylene glycol (average M.W. 1. 6:2

--4 Polyoxyfiropylenc glycol (average M.W. 1:2

-1025 Glycerol 2:3 Di-(2-hydroxyethyl)amine 1:1 Sorbitan mono-oleate.1:1 Moitophenyl ether of trioxypropylene 1:1

ycol. Monoethyl ether of polyoxyethylene 1:1

glycol (average MW. --430). 1,4-di-(2-hydroxyethyl)piperazine. 1:1Mannitol 1:2 Monobcnzyl ether of polyoxypropylene 1:1

glycol (average MW. 510). N -(2-hydroxyethyl)morphollne 1: 1 N ,N' dl(2hydroxyethyhethylene di- 1:2

amine. N ,N-Di-(2-hydroxyethyl)glyc1ne 1:

No'rE.-A=Acylutlng agent of Example 1. B=Acylatlng agent of Exampleeztsy s seat 9! Barnes 4922;.

EXAMPLE 19 An ester is prepared by reacting 600 parts ofpolyisobutenyl-substituted succinic anhydride (average molecularweight-l ,l00) with 230 parts of polypropylene glycol (average molecularweight-425) in the presence of 547 parts of a mineral oil for about 17hours at l50l60 C. while blowing the reaction mixture with nitrogen.Then 32.8 .parts of an acidified clay (commercially available as SuperFiltrol from Filtrol Corporation) is added and the mixture heated toabout 200 C. for an additional 1 1 hours with hydrogen blowing andsubsequently filtered. The filtrate is an oil solution of the desiredester.

EXAMPLE 20 The above ester of Example 1 is posttreated with propyleneoxide by adding 108 parts of propylene oxide to 5,l05 parts of thefiltrate and 25 parts of pyridine while maintaining a temperature of80-90 C. Then the mixture is heated to l 10-l20 C. for 2 to 3 hours andstripped to 170 C. at a pressure of mm. (Hg). The stripped product is anepoxide treated ester.

. EXAMPLE 21 P EXAMPLE 22 Following the procedure of Example 19, apolyisopropenylsubstituted. succinic anhydride (where thepolyisopropenyl substituent has an average molecularweight of about 750)is reacted with mannitol in an equivalent ratio of anhydride to mannitolof 2:3.

' EXAMPLE 23 EXAMPLE 24 An ester is prepared by reacting 2,000 parts ofthe carboxylsuccinic anhydride (average molecular ie acid of Example 1,1,200 parts of the anhydride of Example 19, and 300 parts of sorbitol in1,400 parts of oil following the general procedure of Example 1.

EXAMPLE 25 Amixture of 340 grams (0.3 mole) of alcohol (prepared bycopolymerizing equimolar proportions of styrene and allyl alcohol to acopolymer having a molecular weight of 1,150 and containing an averageof 5 hydroxyl radicals per mole), 1.5 moles of apolyisobutene-substituted succinic anhydride as described in Example 19,and 500 grams of xylene is heated at 80-l 15bL C., diluted with mineraloil, heated to remove xylene, and filtered. The filtrate is posttreatedwith propylene oxide (about one equivalent per equivalent of alcoholused) at 70-l50bL C. under reflux. The desired epoxide posttreatedproduct is diluted with oil to an oil solution having an oil content ofpercent.

EXAMPLE I An ester is prepared according to the general procedure ofExample 21 by reacting the polyisobutenylsubstituted succinic acidanhydride and pentaerythritol in a 1:1 mole ratio. The oil content ofthe ester-containing filtrate is adjusted to about 40 percent.

A. A reaction mixture containing 2,008 parts of the above oil solutionand 73.5 parts of maleic anhydride (the ratio of equivalents of ester tomaleic anhydride is about 1:0.37) is heated to 200 C. over a 1.5-hourperiod, and maintained at 200-210 C. for 5.5 hours. During the last1.5-hour period of heating, the reaction mixture is blown with nitrogen.The mixture is then stripped to 190 C. at 40 mm. (Hg). Thereafter, thereaction mixture is filtered. The filtrate is an oil solution of thedesired posttreated ester.

B. Following thegeneral procedure of (A), 1,506 parts of the estersolution is contacted with 73.5 parts of maleic anhydride. The ratio ofequivalents of ester to maleic anhydride is about 1:05. Again, thedesired posttreated ester is recovered in the form of an oil solution(i.e., the filtrate).

C. Following the general procedure of (A), 1,506 parts of the estersolution is contacted with 147 parts of maleic anhydride producing aratio of equivalents of ester to maleic anhydride of about 1:1. Thereaction mixture is permitted to cool to room temperature and thereafterfiltered to remove unreacted precipitated maleic anhydride.

EXAMPLE 11 An ester is prepared by following the general procedure ofExample 21 by reacting the polyisobutenyl-substituted succinic anhydridewith pentaerythritol in a 1:2 molar ratio. The filtrate thus produced isadjusted to an oil content of about 40 percent.

having a ratio of equivalents of ester to anhydride of 1:025. Uponcompletion of the heating, 583 parts of mineral oil are added and theresulting mixture is filtered. The filtrate is an oil solution of thedesired posttreated ester.

B. Following the general procedure of Example 1(A), 1,670 parts of theabove oil solution of the ester is contacted with 147 parts of maleicanhydride producing a reaction mixture having a ratio of equivalents ofacid to anhydride of 1:0.5. After the heating step is completed, 906parts of mineral oil are added and the resulting'mixture is filtered.The filtrate is an oil solution of the desired posttreated ester.

The foregoing examples illustrate the preferred embodiment of thepresent invention. Following the general procedures of Examples 1 and11, other useful embodiment of the invention are achieved readily bysubstituting for all or a portion of the esters and acylating agentsused therein one or more esters or acylating reagents describedhereinabove. The following table illustrates additional embodimentsprepared following the general procedures of Examples 1 and II but usingthe indicated esters and acylating agents.

TABLE Ester 01 Equivalent example ratio of Example (X) Acylatlng reagent(Y) (X) :(Y)

N o. Sucelnoyl chloride 1:0.33 No. Acetic anhydride 1:0.75 ..No.Pentanoic acid-.... 120.5 No. Phthallc anhydride 120.1 No. 11Ghloromalelc anhydride 1:0.05 No. 14. Laurie acid 1:0.33 No.16. Malelcanhydride 1. 1:0.1 X No.17. Equimolar mixture of formic acid 1:2 andmaleic anhydride. I No. 20. Adlplc acid 1:0.4 XII N0. 24.-." Oleic acid1:11.16

The manner in which the posttreatment improves the properties of theesters is not understood. it is believed that the acylating reagentsprovide increased polarity" to the ester molecules. Thus, the estermolecules are characterized by essentially nonpolar portion (the portionof the acyl moiety characterized by at least about 50 aliphatic carbonatoms) and a polar portion of the ester groups. The reaction ofadditional acid possibly provides additional polarity through theformation of more ester groups, amide groups, amine salt groups and thelike. The additional polarity could account for the improvedsludge-dispersing capabilities. Moreover, when the acylating reagent isa polycarboxylic acid acylating agent, cross-linking is possible. Thiswould result in higher molecular weight esters and this might alsoaccount for improvements in dispersancy as well as improved oilsolubility. Some of the posttreated esters derived from very highmolecular weight acids, for example molecular weights above about10,000, are

characterized by enhanced viscosity index improving capabilities afterposttreatment with polycarboxylic acid acylating reagents.

As mentioned before, the posttreated esters produced by the process ofthis invention are useful as additives in lubricants and fuels in thesame manner as the ester starting materials. They function effectivelyas sludge dispersants in both lubricants and fuels. When employed aslubricating oil additives they are usually present in amounts of fromabout 0.01 percent to about 30 percent by weight in the finallubricating composition. Ordinarily, when used as additives forlubricating oil compositions, the posttreated esters will be present inamounts of from about 0.5 percent to about percent by weight althoughunder unusually adverse conditions, such as in the operation of certaindiesels, they may comprise up to about 30 percent by weight of thelubricant. The products are particularly useful as dispersants inlubricating oil compositions used in the crankcase of various internalcombustion engmes.

The additives of this invention can be effectively employed in a varietyof lubricating compositions based on diverse oils of lubricatingviscosity such as a natural or synthetic lubricating oil, a mixture ofmiscible or mutually soluble natural oils or synthetic oils, or amixture of miscible or mutually soluble natural and synthetic oils. Theterm miscible" is intended to describe that situation where two or moreoils are sufficiently soluble to be compatible as a base oil, whereasthe terminology mutually soluble is intended to describe the situationwhere a suitable common solvent, perhaps another lubricating oil,permits the use of two or more lubricating oils in combination wherethey would not otherwise be compatible due to solubility problems.Typical examples of natural and synthetic oils are identified hereafter.These examples are illustrative and not intended to be exhaustive.

The lubricating compositions contemplated include principally crankcaselubricating oils for spark-ignited and compression-ignited internalcombustion engines including automobile and truck engines, aviationpiston engines, marine and railroad diesel engines, and the like.However, automatic transmission fluids, transaxle lubricants, gearlubricants, metal-working lubricants, hydraulic fluids, and otherlubricating compositions can benefit from the incorporation of thepresent additives. It is also anticipated that the lubricatingcompositions will be thickened or converted to greases by conventionaltechniques well known in the art to form lubricating greases.

Natural oils include animal oils and vegetable oils (e.g., castor oil,lard oil) as well as solvent-refined or acid-refined mineral lubricatingoils of the paraffinic, naphthenic, or mixed paraffinic-naphthenictypes. Oils of lubricating viscosity derived from coal or shale are alsouseful base oils. Synthetic lubricating oils include hydrocarbon oilsand halo-substituted hydrocarbon oils such as polymerized andinterpolymerized olefins (e.g., polybutylenes, polypropylene,propylene-isobutylene copolymers, chlorinated polybutylenes, etc.);alkyl benzenes (e.g., dodecylbenzenes, tetradecylbenzene,dinonylkenzenes, di-(Z-ethylhexyl)benzenes, etc.); polyphenyls (e.g.,biphenyls, terphenyls, etc.); and the like. Alkylene oxide polymers andinterpolymers and derivatives thereof where the terminal hydroxyl groupshave been modified by esterification, etherification, etc., constituteanother class of known synthetic lubricating oils. These are exemplifiedby the oils prepared through polymerization of ethylene oxide orpropylene oxide, the alkyl and aryl ethers of these polyoxyalkylenepolymers (e.g., methylpolyisopropylene glycol ether having averagemolecular weight of 1,00, diphenyl ether of polyethylene glycol having amolecular weight of SOD-1,000, diethyl ether of polypropylene glycolhaving a molecular weight of 1,000 l,500, etc.) or monoandpolycarboxylic esters thereof, for example, the acetic acid esters,mixed C C fatty acid esters, or the C oxo acid diester of tetraethyleneglycol. Another suitable class of synthetic lubricating oils comprisesthe esters of dicarboxylic acids, (e.g., phthalic acid, succinic acid,maleic acid, azelaic acid, suben'c acid, sebacic acid, fumaric acid,adipic acid, linoleic acid dimer, etc.) with a variety of alcohols(e.g., butyl alcohol, hexyl alcohol, dodecyl alcohol, 2-ethylhexylalcohol, pentaerythritol, etc.). Specific examples of these estersinclude dibutyl adipate, di(2-ethylhexyl) sebacate, di-n-hexyl fumarate,dioctyl sebacate, diisooctyl azelate, diisodecyl azelate, dioctylphthalate, didecyl phthalate, dieicosyl sebacate, the 2- ethylhexyldiester of linoleic acid dimer, the complex ester formed by reacting onemole of sebacic acid with two moles of tetraethylene glycol and twomoles of 2-ethyl-hexanoic acid,

and the like. Silicon-based oils such as the polyalkyl-,polyarylpolyalkoxy-, or polyaryloxy-siloxane oils and silicate oilscomprise another useful class of synthetic lubricants, (e.g.,tetraethyl-silicate, tetraisopropyl-silicate,tetra-(2-ethylhexyl)-silicate, tetra-(4-methyl-2-tetraethyl)-silicate,tetra-(ptert-butylphenyl)silicate,hexyl-(4-methyl-2-pentoxy)-disiloxane, poly(methyl)-siloxanes,poly(methylphenyl)-siloxanes, etc.). Other synthetic lubricating oilsinclude liquid esters of phosphorus-containing acids (e.g., tricresylphosphate, trioctyl phosphate, diethyl ester of dune phosphonic acid,etc.), polymeric tetrahydrofurans, and the like.

The posttreated esters may be used alone in a lubricating oilcomposition although they are normally used in conjunction with otherconventional lubricating oil additives of the type illustrated in theabove-identified U.S. patent applications, patents, and Britishspecification. The conventional additives include extreme pressureagents, metal containing detergents such as normal and basic oil-solublealkaline earth metal phenates and petrosulfonates, viscosity indeximproving agents, oxidation inhibitors, antifoam agents, ashlessdispersants, corrosion inhibitors, and the like.

In fuels, the posttreated esters serve to promote engine cleanliness byreducing or eliminating harmful deposits in the fuel system, engine, andexhaust system. They are primarily intended for use in the normallyliquid petroleum distillate fuels, that is, the petroleum distillateswhich boil in the range characteristic of petroleum fuels such asgasolines, fuel oils, diesel fuels, aviation fuels, kerosene, and thelike. When employed in fuels, they are generally employed in lowerconcentrations than in lubricants, for example, in amounts of from about0.001 percent to about 2 percent by weight and generally in amounts offrom about 0.01 percent to about 1 percent by weight. As in the case oflubricants, other conventional additives can be present in the fuelcompositions contemplated by the present invention. Additional additivesinclude lead scavengers, deicers, antiscreen clogging agents,demulsifiers, and the like.

The following are examples of the lubricating and fuel compositionscontemplated by the present invention.

COMPOSITION A SAE 10W-30 mineral lubricating oil containing 1.5 percentof the product of Example I(A) and 0.05 percent of phosphorus as thezinc salt of a phosphorodithioic acid prepared by the reaction ofphosphorus pentasulfide with a mixture of 60 percent (mole)p-butyl-phenol and 40 percent (mole) of n-pentyl alcohol.

Composition B SAE l0W-30 mineral lubricating oil containing 0.75 percentof the product of Example I(B).

COMPOSITION C SAE 30 mineral lubricating oil containing 5 percent of theproduct of Example II(A), 0.1 percent of phosphorus as the zinc salt ofa mixture of equimolar amounts of diisopropyl phosphorodithioic acid anddi-n-decyl phosphorodithioic acid, and 2.5 percent of sulfate ash as abasic barium detergent prepared by carbonating at C. a mixturecomprising mineral oil, barium di-dodecyl-benzenesulfonate, and 1.5moles of barium hydroxide in the presence of a small amount of water and0.7 mole of octylphenol as the promoter.

COMPOSITION D SAE 10 mineral lubricating oil containing 2 percent of theproduct of Example II(B), 0.07 percent of phosphorus zinc dioctylphosphorodithioate, 2 percent of a barium detergent prepared byneutralizing with barium hydroxide the hydrolyzed reaction product ofpolypropylene (molecular weight 2,000) with 1 mole of phosphoruspentasulfide and 1 mole of sulfur, 3 percent of a barium sulfonatedetergent prepared by carbonating a mineral oil solution of mahoganyacid, and a 500 percent stoichiometrically excess amount of bariumhydroxide in the presence of a phenol as the promoter at 180 C., 3percent of a supplemental ashless detergent prepared by copolymerizing amixture of 95 percent (weight) of decylmethacrylate and percent (weight)of diethylaminoethyl acrylate.

COMPOSITION E SAE mineral lubricating oil containing 2 percent of theproduct of Example IV, 0.075 percent of phosphorus as the adduct of zincdi-cyclohexyl phosphorodithioate treated with 0.3 mole of ethyleneoxide, 2 percent of sulfurized sperm oil having a sulfur content of 10percent, 3.5 percent of a poly- (alkyl methacylate) viscosity indeximprover, 0.02 percent of a polyalkylmethacylate), pour pointdepressant, and 0.003 percent of a poly-(alkylsilioxane) antifoam agent.

COMPOSITION F SAE 80 mineral lubricating oil containing 2 percent ofExample XI, 0.1 percent of phosphorus as zinc di-n-hexylphosphorodithioate, 10 percent of chlorinated paraffin wax having achlorine content of 40 percent, 2 percent of di-butyl tetrasulfide, 2percent of sulfurized dipentent, 0.2 percent of oleyl amide, 0.003percent of an antifoam agent, 0.02 percent of a pour point depressant,and 3 percent of a viscosity index improver.

COMPOSITION G SAE W-30 mineral lubricating oil containing 5 percent ofthe product of Example IX.

COMPOSITION II A synthetic lubricating oil which is the complex estersformed by reacting 1 mole of sebacic acid with 2 moles of tetraethyleneglycol and 2 moles of Z-ethyI-hexanoic acid and 3 percent of the productof Example I(A).

COMPOSITION I A synthetic lubricating oil composition with a lubricatingoil is the ester of Z-ethylhexyl alcohol and azelaic acid containing lpercent of the product of Example II(B).

COMPOSITION .l

A diesel fuel containing 0.015 percent of the product of Example I(A).

COMPOSITION K Gasoline containing 0.075 percent of the product ofExample X.

COMPOSITION L Kerosene containing 0.05 percent of the product of ExampleVIII.

The foregoing description of the invention is directed primarily to thepreparation and use of the resulting posttreated esters as additives inlubricants and fuels. However, these posttreated esters may themselvesbe further treated to enhance their dispersant characteristics. Forexample, if as a result of the acid posttreatment, the posttreatedcomposition contains unreacted carboxylic acid acylating groups, furthertreatment of these products with sufficient amine or epoxide toneutralize these groups may be desirable. The alkylene oxides,particularly ethylene oxide and propylene oxide, are especially usefulfor this purpose. Likewise, the al' kylenepolyamines are also veryuseful in neutralizing residual acidity. The ethylene-polyamines(ethylene diamine, pentaethylenehexamine, and the like) or mixturesthereof are preferred for this purpose.

What is claimed is:

l. A lubricating or fuel composition comprising a major amount of,respectively, a lubricating oil or a normally liquid groups in thealcohol moiety where the carboxylic acid moiety of the ester ischaracterized by at least about 50 aliphatic carbon atoms exclusive ofthe carboxyl carbon atoms and the alcohol moiety contains up to about 40aliphatic carbon atoms with (B) at least one acylating reactant selectedfrom monoor polycarboxylic acids having one to about 30 carbon atoms,anhydrides thereof, acyl halides thereof, or mixtures of two or more ofthese acylating agents, in an equivalent reaction of (A) to (B) ofabout110.05 to about 1:5.

2. A composition according to claim 1 where at last a portion of saidoil-soluble ester (A) is characterized by the presence of unreactedhydroxyl groups in the alcoholic moiety as a result of preparing saidoil-soluble: ester (A) by reacting aliphatic monoor polycarboxylic acidacylating agent and polyhydric alcohol in an equivalent ratio ofacylating agent to poayhxdric alcohol of about l:l.05 toabout 1:6.

. composition accordlng to claim 2 where said OlI-SOILI- ble ester (A)is at least one ester of a monoor polycarboxylic acid or anhydride withat least one polyhydric alcohol having three to 10 aliphatic carbonatoms and at least three hydroxyl groups wherein the monoorpolycarboxylic acid or anhydride is one derived from the reaction of apoly (l-monoolefin) or chlorinated poly (l-monoolefin) having averagemolecular weight of about 700 to about 5,000 with an a, B'ethylenicallyunsaturated mono or polycarboxylic acid or anhydride and wherein saidcontacting occurs at a temperature of about C. to about 250 C.

A. A composition according to claim 3 where said acylating reactant (B)is an aliphatic acylating reactant containing one to six carbon atoms.

5. A composition according to claim 4 wherein said polyhydric alcohol isa polyhydric alkanol and said acylating reactant (B) is selected frommaleic anhydride, succinic maleic acid, succinic anhydride, succinincacid, or fumaric acid.

6. A composition according to claim 5 wherein said polyhydric alkanol isselected from the class consisting of glycerol, erythritol,pentaerythritol, mannitol, and sorbitol.

7. A composition according to claim 2 wherein said equivalent ratio ofacylating agent to polyhydric alcohol is about l:l.l to 1:4.

0. A composition according to claim 7 where said oil-soluble ester (A)is at least one ester of a substituted succinic acid wherein thesubstituent is a substantially saturated aliphatic substituentcontaining at least about. 50 aliphatic carbon atoms.

9. A lubricating composition according to claim 8 where said oil-solubleester (A) is a diester of a polyolefin-substituted succinic acid whereinthe polyolefin substituent has a molecular weight of about 700 to about5,000 and not more than about 5 percent of the carbon-to-carbon covalentlinkages in this substituent are unsaturated linkages.

10. A composition according to claim 9 wherein the acylating reactant(B) is an aliphatic acylating agent containing one to six carbon atoms.

11. A composition according to claim 10 wherein said oilsoluble ester(A) is an ester of a polyhydric aliphatic alcohol of up to 10 carbonatoms and characterized by the presence of at least three hydroxylgroups.

12. A composition according to claim lll wherein the polyhydric alcoholis a polyhydric alkanol, the acylating reactant is selected from theclass consisting of maleic anhydride, maleic acid, succinic anhydride,succinic acid, and fumaric acid.

13. A composition according to claim 12 wherein said oilsoluble ester(A) is a diester of polyisobutenyl-substituted succinic acid and apolyhydric alkanol selected from the class consisting of glycerol,erythritol, pentaerythritol, mannitol, and sorbitol.

UNHED STATES PATENT owtct QERMWCMFE @F MERREQTWN Patent No. 51659:2ll2Dated February 197 Inventor(s) William SLKBI It is certified that errorappears in the above-identified patent and that said Letters Patent arehereby corrected as shown below:

At column 14, line 15, that is Claim 1, next to the last line, reactionshould be --1"atio--; at column 14, line 10, that is Claim 5, line 3,delete the term sucoinic"; at column 1 line 47, that is Claim 7, line 3,"11.1 to 1% should be 131,1 to about 1mm Signed and sealed this 5th dayof September 1.972.a

(SEAL) Attest:

EDWARD MmFLETGHEmJRo ROBERT GOTTSGHALK Attesting Officer Commissioner ofPatents FORM PO-105O (10-69) USCOMM-DC 6O376-P69 U.S.GOVERNMEN1 PRlNTlNGQFFICE:19B9 D3G5-334

2. A composition according to claim 1 where at last a portion of saidoil-soluble ester (A) is characterized by the presence of unreactedhydroxyl groups in the alcoholic moiety as a result of preparing saidoil-soluble ester (A) by reacting aliphatic mono-or polycarboxylic acidacylating agent and polyhydric alcohol in an equivalent ratio ofacylating agent to polyhydric alcohol of about 1:1.05 to about 1:6.
 3. Acomposition according to claim 2 where said oil-soluble ester (A) is atleast one ester of a mono- or polycarboxylic acid or anhydride with atleast one polyhydric alcohol having three to 10 aliphatic carbon atomsand at least three hydroxyl groups wherein the mono- or polycarboxylicacid or anhydride is one derived from the reaction of a poly(1-monoolefin) or chlorinated poly (1-monoolefin) having averagemolecular weight of about 700 to about 5,000 with an Alpha , Beta-ethylenically unsaturated mono- or polycarboxylic acid or anhydride andwherein said contacting occurs at a temperature of about 100* C. toabout 250* C.
 4. A composition according to claim 3 where said acylatingreactant (B) is an aliphatic acylating reactant containing one to sixcarbon atoms.
 5. A composition according to claim 4 wherein saidpolyhydric alcohol is a polyhydric alkanol and said acylating reactant(B) is selected from maleic anhydride, succinic maleic acid, succinicanhydride, succininc acid, or fumaric acid.
 6. A composition accordingto claim 5 wherein said polyhydric aLkanol is selected from the classconsisting of glycerol, erythritol, pentaerythritol, mannitol, andsorbitol.
 7. A composition according to claim 2 wherein said equivalentratio of acylating agent to polyhydric alcohol is about 1:1.1 to 1:4. 8.A composition according to claim 7 where said oil-soluble ester (A) isat least one ester of a substituted succinic acid wherein thesubstituent is a substantially saturated aliphatic substituentcontaining at least about 50 aliphatic carbon atoms.
 9. A lubricatingcomposition according to claim 8 where said oil-soluble ester (A) is adiester of a polyolefin-substituted succinic acid wherein the polyolefinsubstituent has a molecular weight of about 700 to about 5,000 and notmore than about 5 percent of the carbon-to-carbon covalent linkages inthis substituent are unsaturated linkages.
 10. A composition accordingto claim 9 wherein the acylating reactant (B) is an aliphatic acylatingagent containing one to six carbon atoms.
 11. A composition according toclaim 10 wherein said oil-soluble ester (A) is an ester of a polyhydricaliphatic alcohol of up to 10 carbon atoms and characterized by thepresence of at least three hydroxyl groups.
 12. A composition accordingto claim 11 wherein the polyhydric alcohol is a polyhydric alkanol, theacylating reactant is selected from the class consisting of maleicanhydride, maleic acid, succinic anhydride, succinic acid, and fumaricacid.
 13. A composition according to claim 12 wherein said oil-solubleester (A) is a diester of polyisobutenyl-substituted succinic acid and apolyhydric alkanol selected from the class consisting of glycerol,erythritol, pentaerythritol, mannitol, and sorbitol.